derivative of ln(ln(ln(x)))
Understand the Problem
The question is asking for the derivative of the function ln(ln(ln(x))). This involves applying the chain rule multiple times, as we have nested logarithmic functions.
Answer
The derivative is $$ \frac{dy}{dx} = \frac{1}{x \ln(x) \ln(\ln(x))} $$
Answer for screen readers
The derivative of the function $y = \ln(\ln(\ln(x)))$ is
$$ \frac{dy}{dx} = \frac{1}{x \ln(x) \ln(\ln(x))} $$
Steps to Solve
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Identify the function and the outermost derivative We start with the function $y = \ln(\ln(\ln(x)))$. The outermost function is the natural logarithm, so we will use the derivative of the natural logarithm, which is $\frac{1}{u}$, where $u$ is the argument of the logarithm.
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Apply the chain rule to the outermost function Taking the derivative of $y$ with respect to $x$, we have: $$ \frac{dy}{dx} = \frac{1}{\ln(\ln(x))} \cdot \frac{d}{dx}[\ln(\ln(x))] $$
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Identify the next inside function and its derivative Now we need to find the derivative of $\ln(\ln(x))$. Again, we apply the chain rule. We denote this new variable as $v = \ln(x)$, so we have: $$ \frac{d}{dx}[\ln(\ln(x))] = \frac{1}{\ln(x)} \cdot \frac{d}{dx}[\ln(x)] $$
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Calculate the derivative of the innermost function The derivative of $\ln(x)$ is $\frac{1}{x}$. Substituting this into the equation, we find: $$ \frac{d}{dx}[\ln(\ln(x))] = \frac{1}{\ln(x)} \cdot \frac{1}{x} $$
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Combine everything together Now we substitute back into the equation we found in step 2: $$ \frac{dy}{dx} = \frac{1}{\ln(\ln(x))} \cdot \left(\frac{1}{\ln(x)} \cdot \frac{1}{x}\right) $$
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Write the final derivative expression This leads us to the final derivative: $$ \frac{dy}{dx} = \frac{1}{x \ln(x) \ln(\ln(x))} $$
The derivative of the function $y = \ln(\ln(\ln(x)))$ is
$$ \frac{dy}{dx} = \frac{1}{x \ln(x) \ln(\ln(x))} $$
More Information
This answer involves the use of the chain rule, which allows us to differentiate composite functions. Understanding the layers of the nested logarithm helps simplify the process of finding the derivative.
Tips
- Confusing the order of derivatives: Make sure to apply the chain rule sequentially and recognize which function is outermost and innermost.
- Forgetting to include all components in the final derivative: Ensure each layer of differentiation is included in the final expression.